The sexual act of placing your shaft in the area between your partner's upper and lower leg (this area is known as the 'legpit' or 'legbow') and then using the area to have sex with. This can accomplished be in a one-on-one situation but is usually reserved in a group sex or gangbang setting where all other areas of traditional sex are taken.
Since Jackie had every hole filled and she was jerking off two other guys my only option was to femur fuck her.
by UberBad March 18, 2005